Diffuser



Oct. 14, 1952 C, D, MaoCRACKEN DIFFUSER s sheets-sheet i Filed May 1,1948 Oct. 14, 1952 Filed May 1, 1948 c. D. MaCcRAcKEN 2,613,587

DIFFUSER 3 Sheets-Sheet 2 Patented Oct. 14, 1952 UNITED STATES PATENT()FFICEr DIFFUSER Calvin D. MacCracken, New Rochelle, N. Y., assignor toJet-Heet, Inc., New York, N. Y., a corporation of New York ApplicationMay 1, 1948, Serial No. 24,537

9 Claims.

This invention relates to a diifuser through which warm air is Asuppliedto a room to be heated. The diffuser serves to mix with very hot air,which is supplied at high velocity by a suitable heating apparatus, airdrawn from the room, so that the resulting air mixture is at amoderately warm temperature and suitable for heating the room; Insteadof being called a diffuser, such a device might be called an airinjector or aspirator.

The diffuser hereinafter described is particularly intended to be usedwith a pipe through which the heating apparatus supplies hot air at atemperature which may be high, for example 310 F. which is about 240 F.above a normally `desired room temperature of 70 F. Since experience hasshown that the temperature of the mixture of hot and room air which issupplied to the room by the diffuser should be in the neighborhood of130 F., the ratio of room air to hot air in the mixture supplied to theroom by the diffuser must be about 3 to 1, when the hot air supplied bythe heating apparatus has the temperature above mentioned. It isdifficult to achieve this ratio in a simple and practical device whichmay be installed in the wall of a room to be heated.

The satisfactory functioning of a diffuser embodying the presentinvention is due particularly to a unique nozzle which is hereinafterdescribed. Having discovered that the amount of aspiration (that is, theratio of cooler air to the hot air in the mixture supplied by thediffuser) depends largely upon the perimeter-area ratio of the mouth ofthe nozzle through which the hot air is emitted, the nozzle in thediffuser about to be described is uniquely designed so that this ratiois high, for example 20 inches to 1 square inch. In the particulardiffuser hereinafter described, the nozzle has a long and rela-- tivelynarrow orifice which is 4sinuous or zig-zag in form out of which a longand relatively thin jet of hot air passes. Moreover, the nozzle is sodesigned and arranged within the casing of the diffuser that the airdrawn from the room, in flowing toward the mouth of the nozzle on bothsides thereof, not only meets but little resistance but flows in contactwith the wall of the nozzle thereby warming the aspirated room air.Another important feature contributing to the satisfactory operation ofthe diffuser hereinafter described is a construction which substantiallyprevents re-circulation within the diffuser of the mixture of hot andcooler air, with the result that sai'd air mixture readily passes intothe room K to be heated. Y Moreover, an important advan- 2 tage of thediffuser hereinafter described is du to the fact that all of the partsthereof which are heated to a high temperature by the very hot airsupplied by the heating apparatus are so well insulated by moving airstreams from the casing of the diffuser that no fire hazard exists.Still another advantage of the diffuser results from the fact that* thecasing is easily mounted `in a wall, and the nozzle is then easilyattachedto the pipe which supplies the hot air,v after which the nozzleis secured in its properposition withi the casing.

The invention will be understood from the following description-of apreferred embodiment thereof which is shown in the accompanyingdrawings. In these drawings, Fig. 1 is a front Lelevation of a diffuserembodying the invention;

, of Fig. 3; Fig. 5 is a plan view of said nozzle element; and Fig. 6 isa perspective view of' said nozzle element. f

The diffuser about to be described is adapted and intended to beinstalled in the space between adjacent studs in a wall of a room to beheated, as will be apparent from Figs. l and 2 in which the outsideportion of a room wall is indicated at I 0 and the back portion isindicated at'lll. The face-plate I2 of the dilfuser is provided withintake and outlet openings, which may be of any form and shape, such asintake louver openings I4 and outlet louver openings I6. The casing i8of the diffuser is located within the wall, and the face-plate Iii-issecured to the casing Iii by screws I9, which also serve to secure thecasingto the wall Hl, as best shown in Fig. 2. In Fig. 2, the nozzle(shown in Figs. 3 to 6 and hereinafter described) is 'shown at ll. Thisnozzle I1 is secured to the back of the casingl i8 by brackets 2U and 2lvwhich at one end may be soldered to the edges of the nozzle, and at theother end may be secured to the back of the diffuser casing i8 by meansof screws 22. The base of the nozzle is provided with a tube v23 whichis adapted to enter an insulated pipe-V24 supplying the hot air, asshown in Fig. 2. It will also be evident from Fig. 2, that theface-plate t2 is provided with an inwardly-extending portion 34 servingas an air-baffling means. cooperating with the nozzle l1, whichsubstantially prevents re-circulation of the hot and cold air-mixtureback into the. path of the room air iiowing toward the nozzle Il, andthus contributes to the satis- 4factory operation ofthe diffuser.`Curved baffles 36 and 38, mounted in the casing I8, serve to divide themixture of hot and room air and direct the divided portions of saidmixture toward the outlet louvers IB.

To permit control of the hot air entering the nozzle I'I through thetube 23, the latter is provided with a damper 30 which is secured to ashaft 32 which is mounted for rotation in the tube 23. As shown in Fig.2, the shaft 32 extends out through a hole in the face-plate I2 and atits outer end is provided with a button 33 which permits manual rotationof the damper 30 so as to regulate or even cut off the flow of hot airto the nozzle I'I. The damper 30 is retained in any position to which itmay be adjusted by the frictional engagement of the ends of springs 35and 36 surrounding the shaft 32 with washers 31 and 38 carried by theshaft 32 and lying against the outside of the tube 23, and with washers39 and 45 also carried by the shaft 32 and cooperating with cotter pins4I and 42 which extend through holes in the shaft 32, as best shown inFig. 4. Fig. 4 also shows manually adjustable means cooperating with thedamper for limiting the extent of the movement of the latter. As shown,this manually adjustable means for limiting the movement of the dampercomprises a rod 43 which is rotatably mounted in opposite walls of thenozzle I'I, and is provided with a projecting finger 45 adapted tocooperate with the damper 30 and limit its movement. The rod 43 at oneend is provided with a slot 46 adapted to receive a screw-driver, and isthreaded so as to receive a nut 4T which may be set up against theoutside of the nozzle wall, thereby squeezing the nozzle wall againstthe shoulder of rod 43 and holding the rod 43 and its finger 45 in anyposition to which it may be adjusted. Thus the extent to which thedamper 30 may be opened by manual manipulation of the button 33 may beadjustably limited.

With the aid of Figs. 3 to 6, the form and construction of the nozzle I1will now be described. It will be apparent that the tube 23 which (ashereinbefore described) is adapted to be attached to the pipe 24 throughwhich the hot air is supplied, is provided at its top with a rectangularplate 50 having a circular opening registering with the opening in' thepipe 23. To the plate 50 are secured upwardly-extending fan-shapedsheet-metal walls 52 and 54 which converge toward one another as theyextend upwardly and cooperate at their upper edges to form a long andnarrow orifice which is sinuous vor zig-zag in form, as will be evidentfrom Figs.

5 and 6. Being of thin sheet-metal the walls 52 and 54 are readilyformed to the shape illustrated in Figs. 3 to 6 in which the bends inthe wall 52 are shown at a, b, c, d, e and j; and the bends in the wall54 are shown at g, h, i, 7', lc and l. The lower edges of the walls 52and 54 are soldered, welded or otherwise secured to the plate 50, wherethey are spaced apart from one another a considerable distance; andalong their side edges 56 and 58 said walls are brought together andsoldered, welded or otherwise secured to one another. In order topreserve the parallel relation of the top edges of the walls 52 and 54,the said walls are spot-welded to one another at their top edges asindicated at 60, 61,'62, 63 and 64. It will be of course understood thatinstead of forming the bends in the walls 52 and 54 with sharp angles,as illustrated in Figs. 5 and 6, the bends may be rounded.

In Fig. 2, the various arrows show how the room air enters the diffuserthrough the intake louvers I4, passes upwardly both in front of andbehind the nozzle I1, and is entrained in and mixed with the hot airescaping in a long and relatively thin jet from the sinuous or Zig-zagaperture in the top of the nozzle; and how the mixture of hot and coolerroom air in passing upwardly is guided by the back and side walls of thecasing I8 and by the baffles 36 and 38 toward the louvers I6 throughwhich the air mixture passes into the room to be heated. It will beobvious that re-circulation of the air mixture is substantiallyprevented by the baille 34, and that the paths traversed by the room airand by the mixture of hot and room air oier little obstruction to freeiiow of the air.

What is claimed is:

1. A diffuser, for supplying to a room hot air mixed with a greateramount of cooler air drawn from the room comprising a casing having anair-intake opening for said cooler air, a nozzle adapted to be connectedto a source supplying hot air at high velocity and having a long andrelatively narrow sinuous or zig-zag orifice and located in said casingin cooperative relation to said air-intake opening, said casing beingprovided with an outlet opening through which the mixture of hot air andcooler air passes into said room.

2. A diffuser, for supplying to a room hot air mixed with a greateramount of cooler air drawn from the room comprising a casing having aface plate provided with an air-intake opening for said cooler air, anozzle adapted to be connected to a source supplying hot air at highvelocity and having a long and. relatively narrow sinuous or zig-zagorice and located in said casing in cooperative relation to saidairintake opening, air baiing means located between said face plate andsaid nozzle for directing the air entering said casing through saidintake opening toward said nozzle and substantially preventingre-circulation of the air mixture within the casing, said casing beingprovided with an outlet opening through which the mixture of hot air andcooler air passes into said room.

3. A diffuser, for supplying to a room hot air mixed with Ya greateramount of cooler air drawn from the room, comprising a casing having aface plate provided with lair-intake and airoutlet openings, a nozzleadapted to be connected to a source supplying hot air at high velocityand having a long and relatively narrow sinuous or zig-zag orifice andlocated in said casing in cooperative relation to said air-intakeopening, and air bailling means projecting from the inside of said faceplate between said openings therein vfor directing the air entering saidcasing toward said nozzle and substantially preventing re-circulation ofthe air mixture within .the casing.

4. A diffuser, for mixing hot air with cool air drawn from a room andredirecting the mixture back into the room, comprising a casing havingspaced apart air-intake and outlet openings, said -casing having an airpassage between said openings, and a nozzle adapted to be connected to asource of hot air and extending into said. passage and having a long andrelatively narrow outlet orice, said orifice following a sinuous orzig-zag path extending from one side of said casing to the other.

5. In a diffuser for supplying to a room hot air mixed with cooler airdrawn from the room,

an air-injector nozzle adapted to be connected to a source of hot airand having a longand relatively narrow sinuous or zig-zag orice forsupplying to the diffuser a long and relatively thin jet of hot air.

6. In a diffuser for supplying to a room hot air mixed with cooler airdrawn from the room, ian air-injector nozzle adapted to be connected toa source of hot air and having fan-shaped Walls arranged in convergingrelation to one another with their top edges parallel and spaced apartthereby forming between them a long and relatively narrow sinuous orzig-zag orifice for supplying to the diffuser a long and relatively thinjet of hot air.

7. In a diffuser for supplying to a room hot air mixed with cooler airdrawn from the room, an air-injector nozzle having a hollow base portionadapted to be connected to a source of hot air, and fan-shaped Wallsconnected to said base portion and arranged in converging relation toone another from said base portion with their top edges parallel to oneanother and spaced Kapart thereby forming between them a long andrelatively narrow sinuous or zig-zag orifice for supplying to thediffuser a long and relatively thin jet of hot air.

8. In a diffuser for supplying to a room hot air mixed with cooler airdrawn from the room, an air-injector nozzle having a hollow base portionadapted to be connected to a source of hot air, and fan-shaped Wallsspaced 4apart at their lower edges and there secured to said baseportion and secured to one another at their side edges, said fan-shapedwalls being arranged in converging relation to one another with theirtopedges parallel to one another and spaced apart thereby formingbetween them a long and relatively narrow sinuous or zig-zag oriceforsupplying to the diffuser a long and relatively thin jet of hot air.

9. 'An air-injector nozzle according to claim 8 having one lor moreconnections between the top edges of said fan-shaped walls forpreserving their spaced-apart relation.

CALVIN D. MACCRACKEN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,090,934 Metcalf et al Mar. 24,1914 '1,140,873 Carter May 25, 1915 1,913,980 Fisher June 13, 19332,000,597 Keyes May 7, 1935 2,119,127 Carrier et al May 31, 19382,122,168 Woolley June 28,1938 2,131,512 Gwinn Sept. 27, 1938l 2,162,923Short June 20, 1939 2,314,569 Baker Mai'. 23, 1943 2,345,537 Keep Mar.28, 1944 FOREIGN PATENTS Number Country Date 379,430 Great Britain Sept.1, 1932 530,178 Great Britain Deo. 6, 1940

